Detection device and display device

ABSTRACT

According to an aspect, a detection device includes: a substrate; detection electrodes arrayed in a row-column configuration in a first direction and a second direction intersecting the first direction in a sensor region of the substrate; a drive circuit configured to supply drive signals to the detection electrodes; wires electrically coupled to the respective detection electrodes; analog front ends each configured to receive, from at least one of the detection electrodes, at least one detection signal corresponding to a capacitance change in the at least one of the detection electrodes caused when the drive signals are supplied; and a multiplexer coupled to one of the detection electrodes via one of the wires and capable of changing the number of the wires simultaneously electrically coupled to one of the analog front ends. The wires extend in the second direction and are disposed side by side in the first direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Application No.2017-218551, filed on Nov. 13, 2017 and Japanese Application No.2018-109813, filed on Jun. 7, 2018, the contents of which areincorporated by reference herein in its entirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a detection device and a displaydevice.

2. Description of the Related Art

Touch detection devices capable of detecting an external proximityobject, or so-called touch panels, have recently been attractingattention. Japanese Patent Application Laid-open Publication No.2009-244958 discloses that a touch panel is mounted on or integratedwith a display device, such as a liquid crystal display device, and usedas a display device with a touch detection function. Japanese PatentApplication Laid-open Publication No. 2017-059262 discloses a touchdetection function of detecting contact of an operator's finger with ascreen and a hover detection (proximity detection) function of detectinga proximity state, a gesture, or the like of the finger not in contactwith the screen.

Touch detection and hover detection are significantly different in adistance between detection electrodes and a detected target objectserving as a detection target, such as a finger, and in the sensitivityrequired for the detection. If electrodes and a drive configuration fortouch detection are used for hover detection without any change,desirable hover detection may be difficult.

SUMMARY

According to an aspect, a detection device includes: a substrate; aplurality of detection electrodes arrayed in a row-column configurationin a first direction and a second direction intersecting the firstdirection in a sensor region of the substrate; a drive circuitconfigured to supply a plurality of drive signals to the detectionelectrodes; a plurality of wires electrically coupled to the respectivedetection electrodes; a plurality of analog front ends each configuredto receive, from at least one of the detection electrodes, at least onedetection signal corresponding to a capacitance change in the at leastone of the detection electrodes caused when the drive signals aresupplied; and a multiplexer coupled to one of the detection electrodesvia one of the wires and capable of changing the number of the wiressimultaneously electrically coupled to one of the analog front ends. Thewires extend in the second direction, and the wires are disposed side byside in the first direction.

According to another aspect, a display device includes: a detectiondevice; and a display panel including a display region. The detectionelectrodes are provided in a region overlapping the display region. Thedetection device includes: a substrate; a plurality of detectionelectrodes arrayed in a row-column configuration in a first directionand a second direction intersecting the first direction in a sensorregion of the substrate; a drive circuit configured to supply aplurality of drive signals to the detection electrodes; a plurality ofwires electrically coupled to the respective detection electrodes; aplurality of analog front ends each configured to receive, from at leastone of the detection electrodes, at least one detection signalcorresponding to a capacitance change in the at least one of thedetection electrodes caused when the drive signals are supplied; and amultiplexer coupled to one of the detection electrodes via one of thewires and capable of changing the number of the wires simultaneouslyelectrically coupled to one of the analog front ends. The wires extendin the second direction, and the wires are disposed side by side in thefirst direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an exemplary configuration of adetection device and a display device according to a first embodiment ofthe present disclosure;

FIG. 2 is a block diagram illustrating an exemplary configuration of adetection circuit;

FIG. 3 is a diagram illustrating a present state for explaining thebasic principle of self-capacitance detection;

FIG. 4 is a diagram illustrating an example of waveforms of a drivesignal and a detection signal in self-capacitance detection;

FIG. 5 is a sectional view illustrating a schematic sectional structureof the detection device and the display device according to the firstembodiment;

FIG. 6 is a plan view schematically illustrating an array substrate;

FIG. 7 is a circuit diagram illustrating a pixel array in a displayregion according to the first embodiment;

FIG. 8 is a perspective view illustrating exemplary arrangement ofdetection electrodes;

FIG. 9 is a diagram for explaining an example of hover detectionaccording to the first embodiment;

FIG. 10 is a diagram for explaining another example of hover detectionaccording to the first embodiment;

FIG. 11 is a diagram illustrating a positional relation between thedetection electrodes and a target object;

FIG. 12 is a diagram for explaining capacitance depending on thedistance between the detection electrode and the target object;

FIG. 13 is a plan view schematically illustrating a relation between thedetection electrodes and a coupling circuit;

FIG. 14 is a diagram for explaining the coupling circuit;

FIG. 15 is a diagram for explaining a specific configuration of amultiplexer illustrated in FIG. 13;

FIGS. 16A to 16D are diagrams for explaining a state where the detectionelectrode supplied with a detection drive signal is sequentiallyswitched;

FIG. 17 is a timing waveform chart for an exemplary operation performedby the display device according to the first embodiment;

FIG. 18 is a diagram for explaining the coupling circuit in which aplurality of detection electrodes are coupled to one analog front end(AFE);

FIG. 19 is a diagram for explaining a detection electrode block;

FIG. 20 is a flowchart for the exemplary operation performed by thedisplay device according to the first embodiment;

FIG. 21 is a graph schematically illustrating a relation between thedetection electrode blocks and signal intensities;

FIG. 22 is a flowchart for an exemplary operation performed by thedisplay device according to a second embodiment of the presentdisclosure;

FIG. 23 is a diagram for schematically explaining changes in the stateof the detection electrodes coupled to the analog front ends;

FIG. 24 is a diagram for explaining the analog front ends coupled to therespective detection electrode blocks in a case where the detectionelectrodes are electrically combined into units of 4×4 detectionelectrodes to serve as the detection electrode blocks;

FIG. 25 is a diagram for explaining the analog front ends coupled to therespective detection electrode blocks in a case where the detectionelectrodes are electrically combined into units of 2×2 detectionelectrodes to serve as the detection electrode blocks;

FIGS. 26A to 26D are diagrams for explaining a state where the detectionelectrodes supplied with the detection drive signals are sequentiallyswitched;

FIG. 27 is a flowchart for an exemplary operation performed by thedisplay device according to a third embodiment of the presentdisclosure;

FIG. 28 is a diagram for schematically explaining changes in the stateof the detection electrodes coupled to the analog front ends;

FIG. 29 is a flowchart for an exemplary operation performed by thedisplay device according to a modification of the third embodiment;

FIG. 30 is a diagram for schematically explaining changes in the stateof the detection electrodes coupled to the analog front ends accordingto the modification of the third embodiment;

FIG. 31 is a diagram for explaining an example of a region on whichtouch detection is performed;

FIG. 32 is a diagram for schematically explaining changes in the stateof the detection electrodes coupled to the analog front ends accordingto a fourth embodiment of the present disclosure;

FIG. 33 is a diagram for explaining the coupling circuit according tothe fourth embodiment;

FIG. 34 is a diagram for schematically explaining a change in thecoupling circuit according to the fourth embodiment in 2×2 collectivehover detection;

FIG. 35 is a diagram for schematically explaining a change in the stateof the coupling circuit according to the fourth embodiment in a firststate, in which the detection electrodes are sequentially switched;

FIG. 36 is a diagram for schematically explaining changes in the stateof the detection electrodes coupled to the analog front ends accordingto a fifth embodiment of the present disclosure;

FIG. 37 is a diagram for explaining the coupling circuit according tothe fifth embodiment;

FIG. 38 is a diagram for schematically explaining a change in the stateof the coupling circuit according to the fifth embodiment in a secondstate, in which the detection electrodes are sequentially switched;

FIG. 39 is a diagram for schematically explaining a change in thecoupling circuit according to the fifth embodiment in 2×2 collectivehover detection;

FIG. 40 is a diagram for schematically explaining a change in the stateof the coupling circuit according to the fifth embodiment in the firststate, in which the detection electrodes are sequentially switched; and

FIG. 41 is a plan view schematically illustrating a relation between thedetection electrodes and the coupling circuit according to a sixthembodiment of the present disclosure.

DETAILED DESCRIPTION

Exemplary aspects (embodiments) to embody the present disclosure aredescribed below in greater detail with reference to the accompanyingdrawings. The contents described in the embodiments are not intended tolimit the present disclosure. Components described below includecomponents easily conceivable by those skilled in the art and componentssubstantially identical therewith. Furthermore, the components describedbelow may be appropriately combined. What is disclosed herein is givenby way of example only, and appropriate changes made without departingfrom the spirit of the present disclosure and easily conceivable bythose skilled in the art naturally fall within the scope of thedisclosure. To simplify the explanation, the drawings may possiblyillustrate the width, the thickness, the shape, and other elements ofeach unit more schematically than the actual aspect. These elements,however, are given by way of example only and are not intended to limitinterpretation of the present disclosure. In the present disclosure andthe figures, components similar to those previously described withreference to previous figures are denoted by like reference numerals,and detailed explanation thereof may be appropriately omitted. In thisdisclosure, when an element A is described as being “on” another elementB, the element A can be directly on the other element B, or there can beone or more elements between the element A and the other element B.

First Embodiment

FIG. 1 is a block diagram illustrating an exemplary configuration of adetection device and a display device according to a first embodiment ofthe present disclosure. FIG. 2 is a block diagram illustrating anexemplary configuration of a detection circuit. As illustrated in FIG.1, a display device 1 includes a display panel 10, a control circuit 11,and a detection circuit 40. The display panel 10 includes a displayregion 20 and a sensor region 30. The display region 20 displays animage. The sensor region 30 is included in the detection device thatdetects touch input. The block diagrams in FIGS. 1 and 2 conceptuallyexplain the configuration, and the detection device and the displaydevice may have another configuration.

The display panel 10 is a display device in which the display region 20and the sensor region 30 are integrated with each other. Specifically,in the display panel 10, part of elements, such as electrodes andsubstrates, of the display region 20 are also used as electrodes andsubstrates of the sensor region 30.

The display region 20 includes a liquid crystal display element servingas a display element. The display region 20 includes a plurality ofpixels each having the display element and has a display surface facingthe pixels. The display region 20 receives video signals to display animage composed of the pixels on the display surface. The display region20 may be an organic electroluminescence (EL) display panel, forexample.

The display panel 10 further includes a coupling circuit 18. Thecoupling circuit 18 is provided between the sensor region 30 and thedetection circuit 40. The coupling circuit 18 switches between couplingand decoupling of detection electrodes DE to be a target of detectiondrive to and from the detection circuit 40, in accordance with controlsignals Vsc1 and Vsc2 supplied from the control circuit 11. The couplingcircuit 18 includes analog front ends (AFE) SC, which will be describedlater.

The control circuit 11 includes a gate driver 12, a source driver 13,and a drive circuit 14. The control circuit 11 supplies control signalsto the gate driver 12, the source driver 13, the drive circuit 14, thecoupling circuit 18, and the detection circuit 40, in accordance withvideo signals Vdisp supplied from the outside, thereby controlling adisplay operation and a detection operation.

The gate driver 12 supplies scanning signals Vscan to one horizontalline to be a target of display drive in the display panel 10, inaccordance with the control signals supplied from the control circuit11. Accordingly, one horizontal line to be a target of display drive issequentially or simultaneously selected.

The source driver 13 is a circuit that supplies pixel signals Vpix torespective sub-pixels SPix (refer to FIG. 7) in the display region 20.Part of the functions of the source driver 13 may be provided to thedisplay panel 10. In this case, the control circuit 11 may generate thepixel signals Vpix and supply them to the source driver 13.

The drive circuit 14 supplies drive signals Vcomdc for display to thedetection electrodes DE of the display panel 10. The drive circuit 14supplies drive signals Vself to the detection electrodes DE serving ascommon electrodes of the display panel 10 via the coupling circuit 18.

The control circuit 11 according to the present embodimenttime-divisionally performs a display mode for performing display in thedisplay region 20 and a detection mode for detecting a target object inthe sensor region 30. The control circuit 11 has two detection modes,that is, a touch detection mode (first detection mode) and a hoverdetection mode (second detection mode). Alternatively, the firstdetection mode and the second detection mode are self-capacitancedetection modes. In the present disclosure, touch detection is referredto as detection of the position of the target object in a state wherethe target object is in contact with a detection surface or the displaysurface or proximate enough to the detection surface or the displaysurface so as to be equated with being in contact therewith(hereinafter, referred to as a “contact state”). Hover detection isreferred to as detection of the position and a movement of the targetobject in a state where the target object is not in contact with thedetection surface or the display surface or not proximate enough to thedetection surface or the display surface so as be equated with being incontact therewith (hereinafter, referred to as a “non-contact state”). A“non-present state” denotes a state where no object to be detected ispresent at a position facing the detection surface or the displaysurface or a state where a target object is too far away from thedisplay surface to be detected in hover detection. A “present state”denotes a state where a target object is present at a position facingthe detection surface or the display surface or a state where a targetobject is away from the display surface but proximate enough to bedetected in hover detection.

A touch sensor in the sensor region 30 has a function of detecting theposition of a target object in contact with or in proximity to thedetection surface or the display surface of the display panel 10 basedon the basic principle for detection of a target object by aself-capacitance method. If the display panel 10 detects contact orproximity of a target object, the display panel 10 outputs detectionsignals Vdet to the detection circuit 40.

The coupling circuit 18 switches between coupling and decoupling of thedetection circuit 40 to and from the detection electrodes DE. In touchdetection, each detection electrode DE is individually coupled to thedetection circuit 40. In hover detection, a plurality of detectionelectrodes DE are combined as a detection electrode block DEB (refer toFIG. 6) and collectively coupled to the detection circuit 40. Thedetection signals Vdet output from the detection electrodes DE aresupplied to the detection circuit 40 via the coupling circuit 18.

In self-capacitance touch detection, the detection circuit 40 uses thedisplay surface of the display panel 10 as the detection surface todetect a target object approaching the detection surface, in accordancewith the drive signals Vself supplied from the drive circuit 14 and thedetection signals Vdet output from the display panel 10. If a touch isdetected, the detection circuit 40 calculates the coordinates at whichthe touch input is performed, for example.

As illustrated in FIG. 2, the detection circuit 40 includes ananalog/digital (A/D) conversion circuit 43, a signal processing circuit44, a coordinate extraction circuit 45, and a detection timing controlcircuit 46. The detection timing control circuit 46 controls the A/Dconversion circuit 43, the signal processing circuit 44, and thecoordinate extraction circuit 45 to operate in synchronization with oneanother, in accordance with the control signals supplied from the drivecircuit 14.

The drive circuit 14 supplies the drive signals Vself to the detectionelectrodes DE, which will be described later, via the analog front endsSC of the coupling circuit 18 (refer to FIG. 1). The detection circuit40 is supplied with the detection signals Vdet from the detectionelectrodes DE, which will be described later, via the analog front endsSC. The analog front ends SC reduce noise in the supplied detectionsignals Vdet and perform signal conditioning such as amplification ofsignal components. The A/D conversion circuit 43 samples analog signalsoutput from the analog front ends SC at a timing synchronized with thedrive signals Vself, thereby converting the analog signals into digitalsignals.

The signal processing circuit 44 is a logic circuit that determineswhether a touch is made on the display panel 10 in accordance with theoutput signals from the A/D conversion circuit 43. The signal processingcircuit 44 performs processing of extracting a signal (absolute value|ΔV|) of a difference between the detection signals caused by a finger.The signal processing circuit 44 compares the absolute value |ΔV| with apredetermined threshold voltage. If the absolute value |ΔV| is lowerthan the threshold voltage, the signal processing circuit 44 determinesthat a target object is in the non-present state. By contrast, if theabsolute value |ΔV| is equal to or higher than the threshold voltage,the signal processing circuit 44 determines that a target object is inthe present state. The detection circuit 40 thus can perform touchdetection or hover detection.

The coordinate extraction circuit 45 is a logic circuit that calculates,if the signal processing circuit 44 detects a target object, thecoordinates of the target object. The coordinate extraction circuit 45outputs the coordinates of the target object as output signals Vout. Thecoordinate extraction circuit 45 may output the output signals Vout tothe control circuit 11. The control circuit 11 can perform apredetermined display operation or detection operation in accordancewith the output signals Vout.

The A/D conversion circuit 43, the signal processing circuit 44, thecoordinate extraction circuit 45, and the detection timing controlcircuit 46 of the detection circuit 40 are provided to the displaydevice 1. The configuration is not limited thereto, and all or part ofthe functions of the detection circuit 40 may be provided to an externalprocessor, for example. The coordinate extraction circuit 45, forexample, may be provided to an external processor different from thedisplay device 1. In this case, the detection circuit 40 may output thesignals processed by the signal processing circuit 44 as the outputsignals Vout.

The display panel 10 performs touch control based on the basic principleof capacitance touch detection. The following describes the basicprinciple for detection of a target object by the self-capacitancemethod performed by the display panel 10 according to the presentembodiment with reference to FIGS. 3 and 4. FIG. 3 is a diagramillustrating the present state for explaining the basic principle ofself-capacitance detection. FIG. 4 is a diagram illustrating an exampleof waveforms of a drive signal and a detection signal inself-capacitance detection. FIG. 3 also illustrates a detection circuit.While the following describes a case where a target object is a finger,it is not limited to a finger and may be an object including aconductor, such as a stylus.

In the non-present state, an AC rectangular wave Sg at a predeterminedfrequency (e.g., a frequency of several kilohertz to several hundredkilohertz) is applied to a detection electrode E1. The detectionelectrode E1 has capacitance C1, and an electric current correspondingto the capacitance C1 flows therethrough. A voltage detector DETconverts fluctuations in electric current depending on the ACrectangular wave Sg into fluctuations in voltage (waveform V0 indicatedby the solid line (refer to FIG. 4)).

As illustrated in FIG. 3, in the present state of a target object,capacitance C2 formed between the finger and the detection electrode E1is added to the capacitance C1 of the detection electrode E1. When theAC rectangular wave Sg is applied to the detection electrode E1, anelectric current corresponding to the capacitance C1 and the capacitanceC2 flows therethrough. As illustrated in FIG. 4, the voltage detectorDET converts fluctuations in electric current depending on the ACrectangular wave Sg into fluctuations in voltage (waveform V1 indicatedby the dotted line). The presence of the target object is measured basedon an absolute value |ΔV| of a difference between the waveform V0 andthe waveform V1.

Specifically, as illustrated in FIG. 4, the voltage level of the ACrectangular wave Sg rises to a voltage V2 at time T01. At this time, aswitch SW1 is turned on, and a switch SW2 is turned off. As a result,the electric potential of the detection electrode E1 also rises to thevoltage V2. Subsequently, the switch SW1 is turned off before time T11.While the detection electrode E1 is in a floating state at this time,the electric potential of the detection electrode E1 is maintained at V2due to the capacitance C1 (or C1+C2, refer to FIG. 3) of the detectionelectrode E1. The voltage detector DET performs a reset operation beforetime T11.

Subsequently, when the switch SW2 is turned on at time T11, the electriccharge accumulated in the capacitance C1 (or C1+C2) of the detectionelectrode E1 moves to capacitance C3 in the voltage detector DET. As aresult, output from the voltage detector DET increases (refer to thedetection signal Vdet in FIG. 4). In the non-present state, the output(detection signal Vdet) from the voltage detector DET corresponds to thewaveform V0 indicated by the solid line, and Vdet=C1×V2/C3 is satisfied.In the present state, the output corresponds to the waveform V1indicated by the dotted line, and Vdet=(C1+C2)×V2/C3 is satisfied.

Subsequently, at time T31, the switch SW2 is turned off, and the switchSW1 and a switch SW3 are turned on. As a result, the electric potentialof the detection electrode E1 is reduced to a low level equal to theelectric potential of the AC rectangular wave Sg, and the voltagedetector DET is reset. The operation described above is repeated at apredetermined frequency (e.g., a frequency of several kilohertz toseveral hundred kilohertz). The detection circuit 40 thus can detect thepresent state of a target object based on the basic principle fordetection of a target object by the self-capacitance method.

The following describes an exemplary configuration of the display device1 according to the present embodiment in greater detail. FIG. 5 is asectional view illustrating a schematic sectional structure of thedetection device and the display device according to the firstembodiment. As illustrated in FIG. 5, the display panel 10 includes anarray substrate 2, a counter substrate 3, and a liquid crystal layer 6serving as a display functional layer. The counter substrate 3 faces thearray substrate 2 in a direction perpendicular to the surface of thearray substrate 2. The liquid crystal layer 6 is interposed between thearray substrate 2 and the counter substrate 3.

The array substrate 2 includes a first substrate 21, pixel electrodes22, the detection electrodes DE, an insulating layer 24, and apolarizing plate 35B. The first substrate 21 is provided with circuits,such as a gate scanner included in the gate driver 12, switchingelements, such as thin-film transistors (TFT), and various kinds ofwiring (not illustrated in FIG. 7), such as gate lines GCL and signallines SGL.

The detection electrodes DE are provided on the upper side of the firstsubstrate 21. The pixel electrodes 22 are provided on the upper side ofthe detection electrodes DE with the insulating layer 24 interposedtherebetween. The pixel electrodes 22 are disposed in a matrix(row-column configuration) in planar view. The pixel electrodes 22correspond to the respective sub-pixels SPix constituting each pixel Pix(refer to FIG. 7) of the display panel 10. The pixel electrodes 22 aresupplied with the pixel signals Vpix for performing a display operation.In the display operation, the detection electrodes DE are supplied withthe drive signals Vcomdc for display to serve as common electrodes for aplurality of pixel electrodes 22. The polarizing plate 35B is providedon the lower side of the first substrate 21.

The pixel electrodes 22 and the detection electrodes DE according to thepresent embodiment are made of a translucent conductive material, suchas indium tin oxide (ITO).

In the present specification, the “upper side” indicates a directionfrom the first substrate 21 toward a second substrate 31 in thedirection perpendicular to the first substrate 21, and the “lower side”indicates a direction from the second substrate 31 toward the firstsubstrate 21.

The pixel electrodes 22 are not necessarily arrayed in a first directionand a second direction orthogonal to the first direction, that is, in amatrix (row-column configuration). Alternatively, a configuration may beemployed in which the pixel electrodes 22 adjacent to each other areshifted in the first direction or the second direction. Stillalternatively, a configuration may be employed in which the pixelelectrodes 22 adjacent to each other have different sizes, and two orthree pixel electrodes 22 are disposed on one side of one pixelelectrode 22 included in a pixel column arrayed in the first direction.

The counter substrate 3 includes the second substrate 31, a color filter32, and a polarizing plate 35A. The color filer 32 is provided on onesurface of the second substrate 31. The polarizing plate 35A is providedon the other surface of the second substrate 31. The color filer 32faces the liquid crystal layer 6 in the direction perpendicular to thefirst substrate 21. The color filter 32 may be disposed on the firstsubstrate 21. The first substrate 21 and the second substrate 31according to the present embodiment are glass substrates or resinsubstrates, for example.

The first substrate 21 and the second substrate 31 face each other witha predetermined space interposed therebetween. The liquid crystal layer6 is interposed between the first substrate 21 and the second substrate31. The liquid crystal layer 6 changes the orientation states of liquidcrystal molecules depending on the state of an electric field formed inthe layer, thereby modulating transmitted light. The electric-field modeis a horizontal electric field mode, such as the in-plane switching(IPS) mode including the fringe field switching (FFS) mode. Orientationfilms (not illustrated in FIG. 5) are provided on the outermost surfaceof the array substrate 2 and the outermost surface of the countersubstrate 3 facing the liquid crystal layer 6 illustrated in FIG. 5. Theorientation films determine the initial orientation states of the liquidcrystal molecules.

An illuminator (backlight), which is not illustrated, is provided on thelower side of the first substrate 21. The illuminator includes a lightsource, such as a light emitting diode (LED), and outputs light from thelight source to the first substrate 21. The light from the illuminatorpasses through the array substrate 2 and is modulated depending on theorientation states of the liquid crystal molecules at a correspondingposition. The state of light transmission to the display surface variesdepending on positions. With this mechanism, an image is displayed onthe display surface.

FIG. 6 is a plan view schematically illustrating the array substrate. Asillustrated in FIG. 6, the display device 1 has a peripheral region 10 boutside a display region 10 a. In the present disclosure, the displayregion 10 a is a region for displaying an image and overlaps a pluralityof pixels Pix (sub-pixels SPix). The peripheral region 10 b is a regioninside the outer periphery of the first substrate 21, and outside thedisplay region 10 a. The peripheral region 10 b may have a frame shapesurrounding the display region 10 a. In this case, the peripheral region10 b may also be referred to as a frame region.

A first direction Dx according to the present embodiment extends alongthe short side of the display region 10 a. A second direction Dy isorthogonal to the first direction Dx. The directions Dx and Dy are notlimited thereto, and the second direction Dy may intersect the firstdirection Dx at an angle other than 90 degrees. The plane defined by thefirst direction Dx and the second direction Dy is parallel to thesurface of the first substrate 21. A third direction Dz intersecting thefirst direction Dx and the second direction Dy is a thickness directionof the first substrate 21.

As illustrated in FIG. 6, the detection electrodes DE are arrayed in amatrix (row-column configuration) in the first direction Dx and thesecond direction Dy in the display region 10 a. The detection electrodeDE has a rectangular or a square shape in planar view. The detectionelectrodes DE are made of a translucent conductive material, such asITO.

A plurality of pixel electrodes 22 are disposed in a matrix (row-columnconfiguration) at a position corresponding to one detection electrodeDE. The area of the pixel electrode 22 is smaller than that of thedetection electrode DE. While FIG. 6 illustrates part of the detectionelectrodes DE and the pixel electrodes 22, they are disposed over thewhole display region 10 a. As described above, the detection electrodesDE are provided in a region overlapping the display region 10 a. In thepresent disclosure, the row direction is also referred to as the firstdirection Dx, and the column direction is also referred to as the seconddirection Dy.

The pixel electrodes 22 are not necessarily arrayed in the firstdirection Dx and the second direction Dy intersecting the firstdirection Dx, that is, in a matrix (row-column configuration).Alternatively, a configuration may be employed in which the pixelelectrodes 22 adjacent to each other are shifted in the first directionDx or the second direction Dy. Still alternatively, a configuration maybe employed in which the pixel electrodes 22 adjacent to each other havedifferent sizes, and two or three pixel electrodes 22 are disposed onone side of one pixel electrode 22 included in a pixel column arrayed inthe first direction Dx.

The coupling circuit 18 and an integrated circuit 19 are provided on ashort side of the peripheral region 10 b. A flexible substrate 71, whichis not illustrated, is coupled to the short side of the peripheralregion 10 b. The flexible substrate 71 is provided with an integratedcircuit of the detection circuit. As illustrated in FIG. 2, theintegrated circuit 19 includes the control circuit 11 and the detectioncircuit 40. Part of the functions of the detection circuit 40 may beincluded in another detection integrated circuit or provided asfunctions of an external micro-processing unit (MPU). The configurationof the integrated circuit 19 is not limited thereto, and the integratedcircuit 19 may be provided to a control substrate outside the module,for example.

The detection electrodes DE are electrically coupled to the integratedcircuit 19 via wires 51 and the coupling circuit 18. The wires 51 areelectrically coupled to the respective detection electrodes DE disposedin the display region 10 a and extend to the peripheral region 10 b. Thewires 51 extend in the second direction Dy and are disposed side by sidein the first direction Dx. The drive circuit 14 (refer to FIG. 1)included in the integrated circuit 19, for example, is coupled to thedetection electrodes DE via the coupling circuit 18 disposed in theperipheral region 10 b and the wires 51.

The following describes a display operation performed by the displaypanel 10. FIG. 7 is a circuit diagram illustrating a pixel array in thedisplay region according to the first embodiment. The first substrate 21(refer to FIG. 5) is provided with switching elements Tr of therespective sub-pixels SPix, the signal lines SGL, the gate lines GCL,and other components as illustrated in FIG. 7. The signal lines SGL arewiring that supplies the pixel signals Vpix to the pixel electrodes 22.The gate lines GCL are wiring that supplies drive signals for drivingthe switching elements Tr. The signal lines SGL and the gate lines GCLextend on a plane parallel to the surface of the first substrate 21.

The display region 20 illustrated in FIG. 7 includes a plurality ofsub-pixels SPix arrayed in a matrix (row-column configuration). Thesub-pixels SPix each include the switching element Tr and liquid crystalLC. The switching element Tr is a thin-film transistor and is ann-channel metal oxide semiconductor (MOS) TFT in this example. Theinsulating layer 24 is provided between the pixel electrodes 22 and thedetection electrodes DE, thereby forming holding capacitance Csillustrated in FIG. 7.

The gate driver 12 illustrated in FIG. 1 sequentially selects the gateline GCL. The gate driver 12 applies the scanning signals Vscan to thegates of the switching elements Tr of the respective sub-pixels SPix viathe selected gate line GCL. As a result, one row (one horizontal line)of sub-pixels SPix out of the sub-pixels SPix is sequentially selectedas a target of display drive. The source driver 13 supplies the pixelsignals Vpix to the sub-pixels SPix included in the selected horizontalline via the signal lines SGL. The sub-pixels SPix perform display on aone horizontal line-by-one horizontal line basis in accordance with thesupplied pixel signals Vpix.

To perform the display operation, the drive circuit 14 applies the drivesignals Vcomdc for display to all the detection electrodes DE. The drivesignal Vcomdc for display is a voltage signal serving as a commonpotential for the sub-pixels SPix. As a result, the detection electrodesDE serve as common electrodes for the pixel electrodes 22 in the displayoperation. To perform display, the drive circuit 14 applies the drivesignals VCOM to all the detection electrodes DE in the display region 10a.

The color filter 32 illustrated in FIG. 5 may include periodicallyarrayed color areas in three colors of red (R), green (G), and blue (B),for example. The color areas 32R, 32G, and 32B in the three colors of R,G, and B, which serve as a set, correspond to the respective sub-pixelsSPix illustrated in FIG. 7. A set of sub-pixels SPix corresponding tothe respective color areas 32R, 32G, and 32B in the three colorsconstitutes one pixel Pix. The color filter 32 may include color areasin four or more colors.

FIG. 8 is a perspective view illustrating exemplary arrangement of thedetection electrodes. As illustrated in FIG. 8, outer edge wiring DE-Gis provided in the peripheral region 10 b on a first surface 21 a of thefirst substrate 21. The outer edge wiring DE-G, for example, is providedcontinuously along the long sides and the short sides of the displayregion 10 a and surrounds the display region 10 a. When the displaydevice 1 performs detection of the present state of a target object, theouter edge wiring DE-G may be supplied with guard signals Vgd having thesame waveform as that of the detection drive signals Vself andsynchronized with the drive signals Vself. Alternatively, the outer edgewiring DE-G may be brought into a state of not being electricallycoupled to any component (high impedance state). This mechanism canprevent generation of capacitance between the outer edge wiring DE-G andthe detection electrodes DE supplied with the drive signals Vself,thereby increasing detection sensitivity for the target object.

The present embodiment may include outer edge wiring 29 on a secondsurface 21 b of the first substrate 21. The outer edge wiring 29 on therear surface may cover part of the second surface 21 b of the firstsubstrate 21 or the entire second surface 21 b. The outer edge wiring 29on the rear surface may be made of a translucent conductive material,such as ITO, or may be a metal frame, which is not illustrated, forexample. When the display device 1 performs detection of the presentstate of a target object, the outer edge wiring 29 on the rear surfacemay be supplied with the guard signals Vgd having the same waveform asthat of the detection drive signals Vself and synchronized with thedrive signals Vself. Alternatively, the outer edge wiring 29 on the rearsurface may be brought into a state of not being electrically coupled toany component (high impedance state). This mechanism can preventgeneration of capacitance between the outer edge wiring 29 on the rearsurface and the detection electrodes DE supplied with the drive signalsVself, thereby increasing sensitivity in hover detection.

FIG. 9 is a diagram for explaining an example of hover detectionaccording to the embodiment. FIG. 10 is a diagram for explaining anotherexample of hover detection according to the embodiment. As illustratedin FIG. 9, the display device 1 performs hover detection when a fingerof an operator serving as a target object is in the non-contact statewith respect to a detection surface DS. The detection circuit 40 candetect a distance D1 between the detection surface DS and the targetobject in a direction perpendicular to the detection surface DS inaccordance with the detection signals Vdet. The detection circuit 40 canalso detect a position R1 of the target object in accordance with thedetection signals Vdet. The position R1 of the target object faces thetarget object in the direction perpendicular to the detection surfaceDS, for example, and corresponds to the detection electrode block DEBhaving the largest value out of the detection signals Vdet supplied froma plurality of detection electrode blocks DEB.

As illustrated in FIG. 10, the display device 1 can detect a movement,such as a gesture, of a target object. When a target object in thenon-contact state with respect to the detection surface DS moves in thedirection of the arrow Da, the detection circuit 40 calculates thechange in position of the target object in accordance with the detectionsignals Vdet. The detection circuit 40 thus detects a movement, such asa gesture, of the target object. Based on the results of hoverdetection, the control circuit 11 (refer to FIG. 1) performs apredetermined display operation or detection operation.

FIG. 11 is a diagram illustrating a positional relation between thedetection electrodes and a target object. FIG. 12 is a diagram forexplaining capacitance depending on the distance between the detectionelectrode and the target object. As illustrated in FIG. 11, when atarget object CQ moves closer to the detection electrodes DE, thedetection signals become easier to be obtained. When the target objectCQ moves farther from the detection electrodes DE, the signal-to-noise(S/N) ratio between the detection signals and noise decreases, wherebythe detection signals become harder to be detected.

As illustrated in FIG. 12, when the distance between the detectionsurface DS and the target object CQ in the third direction Dz is adistance D1 (Step ST101), the target object CQ is in the non-contactstate with respect to the detection surface DS of the display device 1.Capacitance C2 a is formed between the target object CQ and thedetection electrode DE.

Also when the distance between the detection surface DS and the targetobject CQ is a distance D2 (Step ST102), the target object CQ is in thenon-contact state with respect to the detection surface DS of thedisplay device 1. The distance D2 is shorter than the distance D1.Capacitance C2 b is formed between the target object CQ and thedetection electrode DE.

When the distance between the detection surface DS and the target objectCQ is 0 (Step ST103), the target object CQ is in the contact state withrespect to the detection surface DS of the display device 1. CapacitanceC2 c is formed between the target object CQ and the detection electrodeDE.

If the detection electrodes DE are uniform in size, the capacitance C2 bis larger than the capacitance C2 a, and the capacitance C2 c is largerthan the capacitance C2 b. Maintaining detection sensitivity for thetarget object CQ even if the distance between the detection electrode DEand the target object CQ increases only requires increasing the size ofthe detection electrode DE. An increase in the size of the detectionelectrode DE, however, increases the area of one detection electrode DEin the detection surface DS, thereby decreasing detection sensitivity.To address this problem, the display device 1 according to the presentembodiment includes the detection electrodes DE and the coupling circuitdescribed below.

The following describes a relation between the detection electrodes DEand the coupling circuit 18. FIG. 13 is a plan view schematicallyillustrating the relation between the detection electrodes and thecoupling circuit. As illustrated in FIG. 13, the detection electrodes DEare arrayed in a matrix (row-column configuration). Detection electrodesDE(1, 1), DE(1, 2), . . . , and DE(1, n), for example, are arrayed inthe second direction Dy. Detection electrodes DE(1, 1), . . . , andDE(m, 1) are arrayed in the first direction Dx. Similarly, detectionelectrodes DE(m, 1), . . . , and DE(m, n) are arrayed in the seconddirection Dy. The detection electrodes DE(1, 1), . . . , and DE(m, n)are simply referred to as the detection electrodes DE when they need notbe distinguished from one another. In the first embodiment, m is 12, andn is 16, for example. However, m and n are not limited thereto and maytake any desired values.

The detection electrodes DE are made of a translucent conductivematerial, such as ITO. The material of the detection electrodes DE isnot limited to ITO, and the detection electrodes DE may be made of tinoxide, for example.

The coupling circuit 18 switches the coupling state of the detectionelectrodes DE. The coupling circuit 18 according to the presentembodiment includes a multiplexer Mu and analog front ends SC1, . . . ,and SC48. The analog front ends SC1, . . . , and SC48 are simplyreferred to as the analog front ends SC when they need not bedistinguished from one another.

The multiplexer Mu is disposed on the first substrate 21 provided withthe detection electrodes DE and outside the sensor region 30. Similarly,the analog front ends SC are disposed on the first substrate providedwith the detection electrodes DE and outside the sensor region 30. Themultiplexer Mu and the analog front ends SC are made of low-temperaturepolycrystalline silicon, which is polycrystalline silicon produced at alow temperature, for example, and have small areas.

The detection electrodes DE are electrically coupled to the multiplexerMu of the coupling circuit 18 via the respective wires 51. The wires 51illustrated in FIG. 13 are coupled to the respective detectionelectrodes DE(1, 1), DE(1, 2), . . . , and DE(1, n), and the sameapplies to the wires 51 coupled to the other detection electrodes DE,which are not illustrated. The multiplexer Mu is also electricallycoupled to the analog front ends SC.

FIG. 14 is a diagram for explaining the coupling circuit. FIG. 15 is adiagram for explaining a specific configuration of the multiplexerillustrated in FIG. 13. As illustrated in FIG. 14, the coupling circuit18 includes a combination of a plurality of selection circuits ECserving as the multiplexer Mu illustrated in FIG. 13.

As illustrated in FIG. 15, one selection circuit EC includes switchesSW11, SW12, and SW13. The switches SW11, SW12, and SW13 are n-channelMOS TFTs, for example, and provided to the first substrate 21.

Opening and closing of the switches SW11, SW12, and SW13 allow any oneof supply wiring for the drive signals Vcomdc for display, supply wiringfor the guard signals Vgd, and the analog front end SC to be coupled toone detection electrode DE in a time-division manner.

In FIG. 14, the detection electrode DE(1, 2) is coupled to the analogfront end SC2. The detection electrode DE(1, 4) is coupled to the analogfront end SC1. The detection electrode DE(3, 2) is coupled to the analogfront end SC4. The detection electrode DE(3, 4) is coupled to the analogfront end SC3.

In FIG. 14, the detection electrodes DE(1, 1), DE(1, 3), DE(2, 1), DE(2,2), DE(2, 3), DE(2, 4), DE(3, 1), DE(3, 3), DE(4, 1), DE(4, 2), DE(4,3), and DE(4, 4) are coupled to the supply wiring for the guard signalsVgd. The guard signals Vgd have the same waveform as that of thedetection drive signals Vself supplied to the detection electrodes DE(1,2), DE(1, 4), DE(3, 2), and DE(3, 4) and synchronized with the drivesignals Vself. This mechanism can prevent generation of capacitancebetween the detection electrodes DE(1, 2), DE(1, 4), DE(3, 2), and DE(3,4) and the detection electrodes DE(1, 1), DE(1, 3), DE(2, 1), DE(2, 2),DE(2, 3), DE(2, 4), DE(3, 1), DE(3, 3), DE(4, 1), DE(4, 2), DE(4, 3),and DE(4, 4), thereby increasing detection sensitivity for a targetobject.

According to the first embodiment, the number of the analog front endsSC is 48, and the number of the detection electrodes DE is 192. Thenumber of the detection electrodes DE is larger than that of the analogfront ends SC. The multiplexer Mu is coupled to one detection electrodeDE via one wire 51. The multiplexer Mu sequentially electrically couplesthe wires 51 one by one to one analog front end SC in a time-divisionmanner.

FIGS. 16A to 16D are diagrams for explaining a state where the detectionelectrode supplied with the detection drive signal is sequentiallyswitched. As illustrated in FIG. 16A, the detection electrode DE(1, 2)is supplied with the detection drive signal Vself and coupled to theanalog front end SC2 (refer to FIG. 14) by the operations of theselection circuits EC illustrated in FIGS. 14 and 15. The detectionelectrodes DE(1, 1), DE(2, 1), and DE(2,2) are supplied with the guardsignals Vgd.

As illustrated in FIG. 16B, the detection electrode DE(1, 1) is suppliedwith the detection drive signal Vself and coupled to the analog frontend SC2 (refer to FIG. 14) by the operations of the selection circuitsEC illustrated in FIGS. 14 and 15. The detection electrodes DE(1, 2),DE(2, 1), and DE(2, 2) are supplied with the guard signals Vgd.

As illustrated in FIG. 16C, the detection electrode DE(2, 2) is suppliedwith the detection drive signal Vself and coupled to the analog frontend SC2 (refer to FIG. 14) by the operations of the selection circuitsEC illustrated in FIGS. 14 and 15. The detection electrodes DE(1, 1),DE(1, 2), and DE(2, 1) are supplied with the guard signals Vgd.

As illustrated in FIG. 16D, the detection electrode DE(2, 1) is suppliedwith the detection drive signal Vself and coupled to the analog frontend SC2 (refer to FIG. 14) by the operations of the selection circuitsEC illustrated in FIGS. 14 and 15. The detection electrodes DE(1, 1),DE(1, 2), and DE(2, 2) are supplied with the guard signals Vgd.

As described above, the detection circuit 40 can detect self-capacitanceof the detection electrodes DE(1, 1), DE(1, 2), DE(2, 1), and DE(2, 2)via one analog front end SC2. While the coupling configuration of thedetection electrodes DE(1, 1), DE(1, 2), DE(2, 1), and DE(2, 2) havebeen described as an example, the other detection electrodes DE have thesame coupling configuration. As a result, the coupling circuit 18 can bedownsized.

The following describes an exemplary operation according to the presentembodiment with reference to FIG. 1 and FIGS. 13 to 21. FIG. 17 is atiming waveform chart for an exemplary operation performed by thedisplay device according to the first embodiment. FIG. 18 is a diagramfor explaining the coupling circuit in which a plurality of detectionelectrodes are coupled to one analog front end. FIG. 19 is a diagram forexplaining the detection electrode block. FIG. 20 is a flowchart for theexemplary operation performed by the display device according to thefirst embodiment. FIG. 21 is a graph schematically illustrating arelation between the detection electrode blocks and signal intensities.The exemplary operation illustrated in FIGS. 17 to 21 is given by way ofexample only and may be appropriately modified.

As illustrated in FIG. 17, display periods Pd and detection periods Ptare provided such that each of the display periods Pd and each of thedetection periods Pt are alternately arranged in a time-division manner.The detection period Pt includes a hover detection period Pts and atouch detection period Ptm. The execution order of the display periodPd, the hover detection period Pts, and the touch detection period Ptmis given by way of example only and may be appropriately modified. Forexample, one detection period Pt may include only one of the hoverdetection period Pts and the touch detection period Ptm. The displaydevice 1 may perform touch detection on one detection surface in onetouch detection period Ptm or a plurality of touch detection periods Ptmin a divided manner. The display device 1 may display an image of oneframe in one display period Pd. Alternatively, within a period fordisplaying an image of one frame, a plurality of display periods Pd anda plurality of detection periods Pt may be provided such that each ofthe display periods Pd and each of the detection periods Pt arealternately arranged.

As illustrated in FIG. 20, the control circuit 11 writes display datafirst (Step ST1). Specifically, similarly to the display operationdescribed above, the source driver 13 supplies the pixel signals Vpix tothe sub-pixels SPix corresponding to gate lines GCL1, GCL2, and GCL3 viasignal lines SGL1 SGL2, and SGL3. The sub-pixels SPix perform display ona one horizontal line-by-one horizontal line basis in accordance withthe supplied pixel signals Vpix. As illustrated in FIG. 17, the drivecircuit 14 supplies the drive signals Vcomdc for display to thedetection electrodes DE in the display period Pd. The drive signalsVcomdc for display are supplied to all the detection electrodes DE viathe switch SW13 illustrated in FIG. 15 in the coupling circuit 18. Thedetection electrodes DE serve as common electrodes that supply a commonpotential.

Subsequently, the control circuit 11 performs hover detection (StepST2). Specifically, as illustrated in FIG. 17, the control circuit 11supplies the control signal Vsc1 to the coupling circuit 18 and suppliesthe control signal Vsc2 to the coupling circuit 18 in the hoverdetection period Pts. The control signals Vsc1 and Vsc2 turn on theswitch SW11 (refer to FIG. 15) and turn off the switches SW12 and SW13(refer to FIG. 15). Consequently, as illustrated in FIG. 13, fourdetection electrodes DE disposed side by side in the first direction Dxand the second direction Dy are electrically coupled to one another toserve as one detection electrode block DEB.

As illustrated in FIG. 18, for example, the detection electrodes DE(1,1), DE(1, 1), DE(2, 1), and DE(2, 2) are coupled to the same analogfront end SC2 in the coupling circuit 18. When viewed from the detectioncircuit 40 illustrated in FIG. 2, the detection electrodes DE(1, 1),DE(1, 2), DE(2, 1), and DE(2, 2) serve as one detection electrode blockDEB(1, 1) as illustrated in FIG. 19. In other words, the detectionelectrodes DE(1, 1), DE(1, 2), DE(2, 1), and DE(2, 2) electricallycoupled to the respective wires 51 capable of being simultaneouslycoupled to one analog front end SC include at least two detectionelectrodes DE disposed side by side in the first direction Dx or thesecond direction Dy intersecting the first direction Dx on the firstsubstrate 21.

As illustrated in FIG. 13, a plurality of detection electrode blocks DEBare arrayed in a matrix (row-column configuration). Detection electrodeblocks DEB(1, 1), . . . , and DEB(1, N), for example, are arrayed in thesecond direction Dy. Detection electrode blocks DEB(1, 1), . . . , andDEB(M, 1) are arrayed in the first direction Dx. Similarly, detectionelectrode blocks DEB(M, 1), . . . , and DEB(M, N) are arrayed in thesecond direction Dy. The detection electrode blocks DEB(1, 1), . . . ,and DEB(M, N) are simply referred to as the detection electrode blocksDEB when they need not be distinguished from one another. In the firstembodiment, M is 6, and N is 8, for example. However, M and N are notlimited thereto and may take any desired values.

The number of the detection electrode blocks DEB according to the firstembodiment is 48. The detection electrode blocks DEB are eachelectrically coupled to any one of the analog front ends SC1 to SC48 ina one-to-one correspondence by the multiplexer Mu.

The drive circuit 14 supplies the drive signals Vself to the detectionelectrode blocks DEB. The display device 1 thus can detect a targetobject in the non-contact state for each detection electrode block DEB.The detection circuit 40, for example, can detect the distance D1between the detection surface DS and the target object in the directionperpendicular to the detection surface DS, in accordance with thedetection signals Vdet supplied from the respective detection electrodeblocks DEB. The detection circuit 40 can also detect the position R1 ofthe target object in accordance with the detection signals Vdet suppliedfrom the respective detection electrode blocks DEB. The drive circuit 14supplies the guard signals Vgd to the outer edge wiring DE-G (refer toFIG. 8) in the hover detection period Pts.

Subsequently, the detection circuit 40 determines whether the detectionsignals Vdet supplied from the respective detection electrode blocks DEBare equal to or higher than a predetermined threshold ΔVth (Step ST3).As illustrated in FIG. 21, the detection circuit 40 calculates thesignal intensities of the detection signals Vdet supplied from therespective detection electrode blocks DEB and compares them with thepredetermined threshold ΔVth.

If the signal intensity of any one of the detection signals Vdet isequal to or higher than the threshold ΔVth (Yes at Step ST3), thecontrol circuit 11 performs touch detection (Step ST4). If the signalintensity of the detection signal Vdet is equal to or higher than thethreshold ΔVth, the detection circuit 40 determines that a target objectis in the contact state. In the example illustrated in FIG. 21, thesignal intensity of the detection signal Vdet supplied from thedetection electrode block DEB(4, 3) is equal to or higher than thethreshold ΔVth. The signal intensities of the detection signals Vdetsupplied from the other detection electrode blocks DEB are lower thanthe threshold ΔVth. In this case, the detection circuit 40 determinesthat a target object is in the contact state at a position correspondingto the detection electrode block DEB(4, 3). The control circuit 11switches from hover detection to touch detection based on theinformation supplied from the detection circuit 40.

Specifically, as illustrated in FIG. 17, the control circuit 11 suppliesthe control signal Vsc1 to the coupling circuit 18 and supplies thecontrol signal Vsc2 to the coupling circuit 18 in the touch detectionperiod Ptm. The control signals Vsc1 and Vsc2 cause the switches SW11,SW12, and SW13 (refer to FIG. 15) to operate. As a result, asillustrated in FIGS. 16A to 16D, the detection electrode DE suppliedwith the detection drive signal Vself is sequentially switched.

The drive circuit 14 sequentially supplies the drive signals Vself tothe detection electrodes DE. The detection signals Vdet corresponding tocapacitance changes in the detection electrodes DE are supplied to thedetection circuit 40 via the analog front ends SC. The display device 1thus can detect a target object in the contact state in units of aplurality of detection electrodes DE.

In the touch detection period Ptm, when the detection operation on onedetection surface is completed, that is, when the control circuit 11 hassequentially supplied the drive signals Vself to all the detectionelectrodes DE to perform touch detection, the control circuit 11terminates touch detection and returns to writing of display data (StepST1).

If the signal intensities of all the detection signals Vdet are lowerthan the threshold ΔVth (No at Step ST3), the control circuit 11 doesnot perform touch detection and returns to writing of display data (StepST1). In this case, in the detection period Pt illustrated in FIG. 17,the control circuit 11 performs only the processing of the hoverdetection period Pts and does not perform the processing of the touchdetection period Ptm. In other words, only the hover detection periodPts is present in one detection period Pt.

The signal lines SGL are preferably in a floating state in the hoverdetection period Pts and the touch detection period Ptm. This mechanismcan reduce capacitance between the detection electrodes DE and thesignal lines SGL. The gate lines GCL may be in a floating state in thehover detection period Pts.

As described above, the detection device according to the firstembodiment includes the first substrate 21, the detection electrodes DE,the drive circuit 14, the analog front ends SC, and the multiplexer Mu.The detection electrodes DE are provided in the sensor region 30 of thefirst substrate 21. The drive circuit 14 supplies the drive signalsVself to the detection electrodes DE. The analog front ends SC receive,from the detection electrodes DE, the detection signals Vdetcorresponding to capacitance changes in the detection electrodes DEcaused when the drive signals Vself are supplied to the detectionelectrodes DE. The multiplexer Mu is coupled to one detection electrodeDE via one wire 51, and the number of wires 51 simultaneouslyelectrically coupled to one analog front end SC can be changed.

The first embodiment can use the detection electrodes DE in both of thetwo detection modes, that is, in the touch detection mode and the hoverdetection mode by the self-capacitance method. Furthermore, in hoverdetection, the first embodiment changes the number of detectionelectrodes DE combined into one unit depending on the distance betweenthe detection electrodes DE and the target object CQ. Consequently, thefirst embodiment can perform hover detection desirably.

With the configuration described above, the detection device accordingto the first embodiment electrically combines and couples a plurality ofdetection electrodes DE to one analog front end SC, thereby causing themto serve as one detection electrode block DEB if the distance betweenthe detection electrodes DE and the target object CQ is large. Thismechanism increases an apparent size of the detection electrode DE,thereby increasing detection sensitivity for the target object CQ. Anincrease in the size of the detection electrode DE, however, increasesthe area of one detection electrode DE in the detection surface DS,thereby decreasing detection sensitivity. By reducing the number ofdetection electrodes DE coupled to one analog front end SC, thedetection device can increase accuracy in positional coordinates of thetarget object CQ in the present state. As described above, the detectiondevice according to the first embodiment can perform touch detection andhover detection desirably.

Second Embodiment

FIG. 22 is a flowchart for an exemplary operation performed by thedisplay device according to a second embodiment of the presentdisclosure. FIG. 23 is a diagram for schematically explaining changes inthe state of the detection electrodes coupled to the analog front ends.Components described in the first embodiment are denoted by likereference numerals, and explanation thereof is omitted.

The exemplary operation described in the first embodiment is given byway of example only and may be appropriately modified. The displaydevice, for example, may perform hover detection while changing thenumber of detection electrodes DE serving as one detection electrodeblock DEB in a plurality of hover detection periods Pts. The controlcircuit 11 can change a resolution in hover detection by changing thenumber of detection electrodes DE included in one detection electrodeblock DEB depending on the distance D1 between the detection surface DSand a target object.

Also in FIG. 22, the display periods Pd and the detection periods Ptprovided such that each of the display periods Pd and each of thedetection periods Pt are alternately arranged in a time-division manner.Detailed explanation of the display period Pd is omitted because it isthe same as that described in the first embodiment. In the detectionperiod Pt according to the second embodiment, the detection electrodesare electrically combined into units of 4×4 detection electrodes by thecoupling circuit 18 to serve as the detection electrode blocks DEB. Thecontrol circuit 11 performs hover detection (Step ST11).

As illustrated in FIG. 23, the size of the detection electrode block DEBis large at step ST11. This configuration facilitates detecting thetarget object CQ even if the distance between the target object CQ andthe detection electrode blocks DEB is large.

FIG. 24 is a diagram for explaining the analog front ends coupled to therespective detection electrode blocks in a case where the detectionelectrodes are electrically combined into units of 4×4 detectionelectrodes to serve as the detection electrode blocks. In FIG. 24, 12×16detection electrodes DE are electrically combined into units of 4×4detection electrodes DE to serve as the detection electrode blocks DEB.As a result, 3×4 detection electrode blocks DEB are arrayed in a matrix(row-column configuration).

In FIG. 24, the detection electrode blocks DEB include detectionelectrode blocks DEBB(1, 1), DEBB(1, 2), DEBB(1, 3), DEBB(1, 4), DEBB(2,1), DEBB(2, 2), DEBB(2, 3), DEBB(2, 4), DEBB(3, 1), DEBB(3, 2), DEBB(3,3), and DEBB(3, 4).

As illustrated in FIG. 13, the coupling circuit 18 according to thesecond embodiment also includes the multiplexer Mu and the analog frontends SC1, . . . , and SC48. The detection electrodes DE included in thedetection electrode block DEBB(1, 1) are electrically coupled to theanalog front end SC37. The detection electrodes DE included in thedetection electrode block DEBB(1, 2) are electrically coupled to theanalog front end SC25. The detection electrodes DE included in thedetection electrode block DEBB(1, 3) are electrically coupled to theanalog front end SC13. The detection electrodes DE included in thedetection electrode block DEBB(1, 4) are electrically coupled to theanalog front end SC1.

The detection electrodes DE included in the detection electrode blockDEBB(2, 1) are electrically coupled to the analog front end SC41. Thedetection electrodes DE included in the detection electrode blockDEBB(2, 2) are electrically coupled to the analog front end SC29. Thedetection electrodes DE included in the detection electrode blockDEBB(2, 3) are electrically coupled to the analog front end SC17. Thedetection electrodes DE included in the detection electrode blockDEBB(2, 4) are electrically coupled to the analog front end SC5.

The detection electrodes DE included in the detection electrode blockDEBB(3, 1) are electrically coupled to the analog front end SC45. Thedetection electrodes DE included in the detection electrode blockDEBB(3, 2) are electrically coupled to the analog front end SC33. Thedetection electrodes DE included in the detection electrode blockDEBB(3, 3) are electrically coupled to the analog front end SC21. Thedetection electrodes DE included in the detection electrode blockDEBB(3, 4) are electrically coupled to the analog front end SC9.

As illustrated in FIG. 23, at Step ST11, the detection circuit 40detects self-capacitance in accordance with the detection signals Vdetsupplied from the detection electrode blocks DEBB(1, 1), DEBB(1, 2),DEBB(1, 3), DEBB(1, 4), DEBB(2, 1), DEBB(2, 2), DEBB(2, 3), DEBB(2, 4),DEBB(3, 1), DEBB(3, 2), DEBB(3, 3), and DEBB(3, 4) via the 12 analogfront ends SC out of the 48 analog front ends SC. The detection circuit40 thus determines which of the detection electrode blocks DEBBcorresponds to the position of the target object CQ.

Subsequently, the detection circuit 40 compares the intensities of thesupplied detection signals Vdet with a predetermined threshold ΔVtha anddetermines whether the signal intensities are equal to or higher thanthe predetermined threshold ΔVtha (Step ST12).

If the signal intensity of any one of the detection signals Vdet islower than the threshold ΔVtha (No at Step ST12), the control circuit 11returns to the processing at Step ST11. If the signal intensity of anyone of the detection signals Vdet is equal to or higher than thethreshold ΔVtha (Yes at Step ST12), the detection electrodes areelectrically combined into units of 2×2 detection electrodes by thecoupling circuit 18. As illustrated in FIG. 23, the 2×2 detectionelectrodes serve as one detection electrode block DEB smaller than thedetection electrode block DEB obtained at Step ST11. The control circuit11 then performs hover detection (Step ST13).

FIG. 25 is a diagram for explaining the analog front ends coupled to therespective detection electrode blocks in a case where the detectionelectrodes are electrically combined into units of 2×2 detectionelectrodes to serve as the detection electrode blocks. In FIG. 25, 12×16detection electrodes DE are electrically combined into units of 2×2detection electrodes DE to serve as the detection electrode blocks DEB.As a result, 6×8 detection electrode blocks DEB are arrayed in a matrix(row-column configuration).

The detection electrodes DE included in the detection electrode blockDEB(1, 1) are electrically coupled to the analog front end SC39. Thedetection electrodes DE included in the detection electrode block DEB(1,2) are electrically coupled to the analog front end SC37. Similarly, thedetection electrodes DE included in the other detection electrode blocksDEB are electrically coupled to the analog front ends SC denoted by thereference numerals written in the detection electrodes DE in FIG. 25.

At Step ST13, the detection circuit 40 detects self-capacitance inaccordance with the detection signals Vdet supplied from the detectionelectrode blocks DEB via 48 analog front ends SC out of the 48 analogfront ends SC, as illustrated in FIG. 25. The detection circuit 40 thusdetermines which detection electrode block DEB out of the detectionelectrode blocks DEB corresponds to the position of the target objectCQ.

Subsequently, the detection circuit 40 determines whether the detectionsignals Vdet supplied from the respective detection electrode blocks DEBillustrated in FIG. 25 are lower than a predetermined threshold ΔVthb(Step ST14). If the detection signals Vdet supplied from the respectivedetection electrode blocks DEB illustrated in FIG. 25 are lower than thepredetermined threshold ΔVthb (Yes at Step ST14), the detection circuit40 returns to the processing at Step ST11. If the detection signals Vdetsupplied from the respective detection electrode blocks DEB illustratedin FIG. 25 are lower than the predetermined threshold ΔVthb, thedistance between the target object CQ and the detection electrodes DE isassumed to be large. The larger the distance between the target objectCQ and the detection electrodes DE, the larger the number of wires 51,via which the control circuit 11 transmits the control signals to thecoupling circuit 18, and which are simultaneously electrically coupledto one analog front end SC. This processing increases detectionsensitivity, thereby increasing a possibility of detecting the targetobject CQ.

If the detection signals Vdet supplied from the respective detectionelectrode blocks DEB illustrated in FIG. 25 are equal to or higher thanthe predetermined threshold ΔVthb (No at Step ST14), the detectioncircuit 40 performs the processing at Step ST15.

Subsequently, the detection circuit 40 determines whether the detectionsignals Vdet supplied from the respective detection electrode blocks DEBillustrated in FIG. 25 are equal to or higher than a predeterminedthreshold ΔVthc that is larger than the predetermined threshold ΔVthb(Step ST15). If the detection signals Vdet supplied from the respectivedetection electrode blocks DEB illustrated in FIG. 25 are lower than thepredetermined threshold ΔVthc (No at Step ST15), the detection circuit40 returns to the processing at Step ST13.

If the detection circuit 40 determines that the detection signals Vdetsupplied from the respective detection electrode blocks DEB illustratedin FIG. 25 are equal to or higher than the predetermined threshold ΔVthc(Yes at Step ST15), the control circuit 11 performs touch detection(Step ST16). If the detection signals Vdet supplied from the respectivedetection electrode blocks DEB illustrated in FIG. 25 are equal to orhigher than the predetermined threshold ΔVthc (Yes at Step ST15), thedistance between the target object CQ and the detection electrodes DE isassumed to be small. The smaller the distance between the target objectCQ and the detection electrodes DE, the smaller the number of wires 51,via which the control circuit 11 transmits the control signals to thecoupling circuit 18, and which are simultaneously electrically coupledto one analog front end SC.

At Step ST16, similarly to the first embodiment, the coupling circuit 18sequentially switches the detection electrodes DE supplied with thedetection drive signals Vself. As illustrated in FIG. 23, the couplingcircuit 18 according to the second embodiment selects and couples thedetection electrodes DE included in one row to the analog front ends SCand sequentially shifts the detection electrodes DE included in one rowfrom Step ST161 to Step ST164. While the coupling circuit 18sequentially shifts row by row the detection electrodes DE included inone row in the present disclosure, it may sequentially shift column bycolumn the detection electrodes DE included in one column.

FIGS. 26A to 26D are diagrams for explaining a state where the detectionelectrodes supplied with the detection drive signals are sequentiallyswitched. As illustrated in FIG. 26A, the coupling circuit 18 selectsthe detection electrodes DE in the fourth, the eighth, the twelfth, andthe sixteenth rows. The coupling circuit 18 couples the detectionelectrodes DE in the fourth, the eighth, the twelfth, and the sixteenthrows to the analog front ends SC denoted by the reference numeralswritten in the respective detection electrodes DE in FIG. 26A (refer toStep ST161 in FIG. 23).

As illustrated in FIG. 26B, the coupling circuit 18 selects thedetection electrodes DE in the third, the seventh, the eleventh, and thefifteenth rows. The coupling circuit 18 couples the detection electrodesDE in the third, the seventh, the eleventh, and the fifteenth rows tothe analog front ends SC denoted by the reference numerals written inthe respective detection electrodes DE in FIG. 26B (refer to Step ST162in FIG. 23).

As illustrated in FIG. 26C, the coupling circuit 18 selects thedetection electrodes DE in the second, the sixth, the tenth, and thefourteenth rows. The coupling circuit 18 couples the detectionelectrodes DE in the second, the sixth, the tenth, and the fourteenthrows to the analog front ends SC denoted by the reference numeralswritten in the respective detection electrodes DE in FIG. 26C (refer toStep ST163 in FIG. 23).

As illustrated in FIG. 26D, the coupling circuit 18 selects thedetection electrodes DE in the first, the fifth, the ninth, and thethirteenth rows. The coupling circuit 18 couples the detectionelectrodes DE in the first, the fifth, the ninth, and the thirteenthrows to the analog front ends SC denoted by the reference numeralswritten in the respective detection electrodes DE in FIG. 26D (refer toStep ST164 in FIG. 23).

In FIGS. 26A to 26D, the detection electrodes DE without any referencenumeral of an analog front end SC are coupled to no analog front end SC.

As described above, the detection electrodes DE included in one row aresequentially shifted. Consequently, the detection circuit 40 can obtainthe signal intensities of the detection signals Vdet of all thedetection electrodes DE even if the number of the analog front ends SCis smaller than that of all the detection electrodes DE.

Subsequently, the detection circuit 40 determines whether the detectionsignals Vdet supplied from the detection electrode blocks DEBillustrated in FIGS. 26A to 26D are lower than a predetermined thresholdΔVthd (Step ST17). If the detection signals Vdet supplied from thedetection electrode blocks DEB illustrated in FIGS. 26A to 26D are lowerthan the predetermined threshold ΔVthd (Yes at Step ST17), the detectioncircuit 40 returns to the processing at Step ST13. This processingincreases detection sensitivity, thereby increasing a possibility ofdetecting the target object CQ.

If the detection circuit 40 determines that the detection signals Vdetsupplied from the detection electrode blocks DEB illustrated in FIGS.26A to 26D are equal to or higher than the predetermined threshold ΔVthd(No at Step ST17), the detection circuit 40 extracts the coordinates ofthe target object CQ and then terminates the processing.

Third Embodiment

FIG. 27 is a flowchart for an exemplary operation performed by thedisplay device according to a third embodiment of the presentdisclosure. FIG. 28 is a diagram for schematically explaining changes inthe state of the detection electrodes coupled to the analog front ends.Components described in the first and the second embodiments are denotedby like reference numerals, and explanation thereof is omitted.

Also in FIG. 27, the display periods Pd and the detection periods Pt areprovided such that each of the display periods Pd and each of thedetection periods Pt are alternately arranged in a time-division manner.Detailed explanation of the display period Pd is omitted because it isthe same as that described in the first embodiment. In the detectionperiod Pt according to the third embodiment, the detection electrodesare electrically combined into units of 4×4 detection electrodes by thecoupling circuit 18 to serve as the detection electrode blocks DEB. Thecontrol circuit 11 performs hover detection (Step ST21). Detailedexplanation of the processing at Step ST21 is omitted because it is thesame as the processing at Step ST11.

Subsequently, the detection circuit 40 calculates the intensities of thesupplied detection signals Vdet, compares the intensities of thedetection signals Vdet with the predetermined threshold ΔVtha, anddetermines whether the signal intensities are equal to or higher thanthe predetermined threshold ΔVtha (Step ST22).

If the signal intensity of any one of the detection signals Vdet islower than the threshold ΔVtha (No at Step ST22), the control circuit 11returns to the processing at Step ST21. If the signal intensity of anyone of the detection signals Vdet is equal to or higher than thethreshold ΔVtha (Yes at Step ST22), the detection electrodes areelectrically combined into units of 2×2 detection electrodes by thecoupling circuit 18. As illustrated in FIG. 28, the 2×2 detectionelectrodes serve as one detection electrode block DEB smaller than thedetection electrode block DEB obtained at Step ST21. The control circuit11 then performs hover detection (Step ST23).

Subsequently, the detection circuit 40 determines whether the detectionsignals Vdet supplied from the respective detection electrode blocks DEBillustrated in FIG. 28 are lower than the predetermined threshold ΔVthb(Step ST24). If the detection signals Vdet supplied from the respectivedetection electrode blocks DEB illustrated in FIG. 28 are lower than thepredetermined threshold ΔVthb (Yes at Step ST24), the detection circuit40 returns to the processing at Step ST21. This processing increasesdetection sensitivity, thereby increasing a possibility of detecting thetarget object CQ.

If the detection signals Vdet supplied from the respective detectionelectrode blocks DEB illustrated in FIG. 28 are equal to or higher thanthe predetermined threshold ΔVthb (No at Step ST24), the detectioncircuit 40 performs the processing at Step ST25.

If the detection circuit 40 determines that the detection signals Vdetsupplied from the respective detection electrode blocks DEB illustratedin FIG. 28 are equal to or higher than the predetermined threshold ΔVthb(No at Step ST24), the control circuit 11 performs touch detection (StepST25).

As illustrated in FIG. 28, the third embodiment performs touch detectionon the detection electrode block DEB determined to have a signalintensity equal to or higher than the predetermined threshold ΔVthb atStep ST24 and on the detection electrodes DE around the detectionelectrode block DEB.

As described above, in hover detection, the control circuit 11determines the detection electrodes DE on which touch detection isperformed based on the detection electrode block DEB determined to havea signal intensity equal to or higher than the predetermined thresholdΔVthb and on a region around the detection electrode block DEB. Thecontrol circuit 11 performs touch detection on the determined detectionelectrodes DE and the detection electrodes DE adjacent to the determineddetection electrodes DE.

Consequently, the third embodiment need not detect capacitance of allthe detection electrodes DE and can shorten the detection period Pt.Alternatively, the third embodiment may increase the number of times ofdetection performed on a certain detection electrode DE to be adetection target in the detection period Pt, thereby increasingdetection accuracy.

FIG. 29 is a flowchart for an exemplary operation performed by thedisplay device according to a modification of the third embodiment. FIG.30 is a diagram for schematically explaining changes in the state of thedetection electrodes coupled to the analog front ends according to themodification of the third embodiment. Components described in the thirdembodiment are denoted by like reference numerals, and explanationthereof is omitted.

The modification of the third embodiment is different from the thirdembodiment in that a plurality of objects to be detected are present.The processing from Step ST21 to Step ST24 in FIG. 29 is the same as theprocessing according to the third embodiment. As illustrated in FIG. 30,a target object CQ1 and a target object CQ2 are in the present state.

As illustrated in FIG. 30, if the number of detection electrodes DEincluded in the detection electrode block DEB determined to have asignal intensity equal to or higher than the predetermined thresholdΔVthb at Step ST24 and the number of detection electrodes DE around thedetection electrode block DEB exceed the number of analog front ends SCincluded in the coupling circuit 18, the modification of the thirdembodiment performs touch detection on two regions.

As illustrated in FIG. 30, the control circuit 11 performs touchdetection on the detection electrode block DEB determined to have asignal intensity equal to or higher than the predetermined thresholdΔVthb, which is assumed to be caused by the target object CQ1, and onthe region around the detection electrode block DEB.

FIG. 31 is a diagram for explaining an example of the region on whichtouch detection is performed. As illustrated in FIG. 31, the detectionelectrode block determined to have a signal intensity equal to or higherthan the predetermined threshold ΔVthb is the detection electrode blocksDEB(3, 7), DEB(3, 8), DEB(4, 7), and DEB(4, 8). The coupling circuit 18couples the analog front ends SC41, SC42, SC43, SC44, SC29, SC30, SC31,SC32, SC17, SC18, SC19, SC20, SC5, SC6, SC7, and SC8 to the detectionelectrodes DE included in the corresponding detection electrode blocksDEB(3, 7), DEB(3, 8), DEB(4, 7), and DEB(4, 8). The detectionsensitivity in coordinate extraction is lower in detecting the targetobject CQ1 in units of the detection electrode blocks DEB than in unitsof the detection electrodes DE. For this reason, it is preferable toperform touch detection also on the detection electrodes DE around thedetection electrode blocks DEB(3, 7), DEB(3, 8), DEB(4, 7), and DEB(4,8).

The coupling circuit 18 electrically couples the detection electrodes DEsurrounded by the detection electrodes DE(1, 13), DE(1, 16), DE(12, 13),and DE(12, 16) to the analog front ends SC denoted by the referencenumerals written in the respective detection electrodes DE in FIG. 31.

Subsequently, as illustrated in FIG. 30, the control circuit 11 performstouch detection on the detection electrode block DEB determined to havea signal intensity equal to or higher than the predetermined thresholdΔVthb and on the region around the detection electrode block DEB inanother region different from that determined to be a target at StepST25 (Step ST26).

Fourth Embodiment

FIG. 32 is a diagram for schematically explaining changes in the stateof the detection electrodes coupled to the analog front ends accordingto a fourth embodiment of the present disclosure. FIG. 33 is a diagramfor explaining the coupling circuit according to the fourth embodiment.FIG. 34 is a diagram for schematically explaining a change in thecoupling circuit according to the fourth embodiment in 2×2 collectivehover detection. FIG. 35 is a diagram for schematically explaining achange in the state of the coupling circuit according to the fourthembodiment in a first state, in which the detection electrodes aresequentially switched. Components described in the first to the thirdembodiments are denoted by like reference numerals, and explanationthereof is omitted. Detection electrodes DE(1, n) to DE(1, n−15) andDE(2, n) to DE(2, n−15) illustrated in FIGS. 33 to 35 exemplify part ofthe detection electrodes DE illustrated in FIG. 13, and the specificshape thereof is a rectangular shape as illustrated in FIG. 13.

As illustrated in FIG. 32, the coupling circuit 18 illustrated in FIG.33 switches between a step for hover detection (Step ST32) and a stepfor touch detection (Step ST33 or Step ST34).

The coupling circuit 18 illustrated in FIG. 33 includes switches Mux1,Mux2, and Mux3. The coupling circuit 18 illustrated in FIG. 33 includesa relay wire DEL(1, n) coupled to the detection electrode DE(1, n) viathe switch Mux1. Similarly, the detection electrodes DE(1, n−1) to DE(1,n−15) are coupled to relay wires DEL(1, n−1) to DEL(1, n−15),respectively, via the switch Mux1. The detection electrodes DE(2, n) toDE(2, n−15) are coupled to relay wires DEL(2, n) to DEL(2, n−15),respectively, via the switch Mux1. The term “relay wire DEL” is used tosimply explain any one of the relay wires DEL(1, n) to DEL(1, n−15) andDEL(2, n) to DEL(2, n−15).

The switch Mux1 couples the detection electrodes DE to the supply wiringfor the drive signals Vcomdc for display, the supply wiring for theguard signals Vgd, or the respective relay wires DEL coupled to theanalog front ends SC. The relay wire DEL couples the switch Mux1 and theswitch Mux2 and couples the switch Mux1 and the switch Mux3. Opening andclosing of the switches Mux1, Mux2, and Mux3 allow any one of the supplywiring for the drive signals Vcomdc for display, the supply wiring forthe guard signals Vgd, and the analog front end SC to be coupled to onedetection electrode DE in a time-division manner.

At Step ST32 illustrated in FIG. 32, the switch Mux2 decouples the relaywires DEL from the analog front ends SC. As illustrated in FIG. 34, theswitch Mux3 and the relay wires DEL electrically couple the detectionelectrodes DE disposed side by side in the first direction Dx and thesecond direction Dy. The switch Mux3 and the relay wires DEL thuscombine 2×2 detection electrodes DE, thereby forming detection electrodeblocks DEB(1, N) to DEB(1, N−7). The detection electrode blocks DEB(1,N) to DEB(1, N−7) are coupled to the analog front ends SC1 to SC7,respectively. The control circuit 11 illustrated in FIG. 1 then performshover detection (Step ST32).

If the detection signals Vdet supplied from the respective detectionelectrode blocks DEB illustrated in FIG. 34 are equal to or higher thanthe predetermined threshold ΔVthb, the detection circuit 40 performs theprocessing at Step ST33.

At Step ST33, the fourth embodiment performs touch detection on thedetection electrode block DEB determined to have a signal intensityequal to or higher than the predetermined threshold ΔVthb and on thedetection electrodes DE around the detection electrode block DEB.

At Step ST33, for example, the detection electrode block DEB(1, N) isdetermined to have a signal intensity equal to or higher than thepredetermined threshold ΔVthb. In this case, as illustrated in FIG. 35,the control circuit 11 performs touch detection on the detectionelectrodes DE(1, n), DE(1, n−1), DE(2, n), and DE(2, n−1) correspondingto the detection electrode block DEB(1, N) (Step ST33).

The switch Mux3 decouples the relay wires DEL from the analog front endsSC. The switch Mux1 electrically couples the detection electrodes DE(1,n), DE(1, n−1), DE(1, n−2), and DE(1, n−3) to the relay wires DEL(1, n),DEL(1, n−1), DEL(1, n−2), and DEL(1, n−3), respectively. The switch Mux1couples the other detection electrodes DE to the supply wiring for theguard signals Vgd.

The switch Mux2 couples the analog front end SC1 to the relay wireDEL(1, n) and couples the analog front end SC5 to the relay wire DEL(2,n). The switch Mux2 then couples the analog front end SC1 to the relaywire DEL(1, n−1) and couples the analog front end SC5 to the relay wireDEL(2, n−1). The switch Mux2 then couples the analog front end SC1 tothe relay wire DEL(1, n−2) and couples the analog front end SC5 to therelay wire DEL(2, n−2). The switch Mux2 then couples the analog frontend SC1 to the relay wire DEL(1, n−3) and couples the analog front endSC5 to the relay wire DEL(2, n−3). With this processing, the detectionelectrodes DE disposed side by side in the first direction Dx aresimultaneously selected and coupled to the analog front ends SC. Withthe operations of the switch Mux2, the detection electrodes DE coupledto the analog front ends SC are sequentially switched in the seconddirection Dy.

After the processing at Step ST33 illustrated in FIG. 32, the controlcircuit 11 performs touch detection on another detection electrode blockDEB determined to have a signal intensity equal to or higher than thepredetermined threshold ΔVthb at Step ST32 and on the detectionelectrodes DE around the detection electrode block DEB (Step ST34).Detailed explanation of the processing at Step ST34 is omitted becauseit is the same as the processing at Step ST33 except that the positionsof the detection electrodes DE coupled to the analog front ends SC inthe second direction Dy are different.

Fifth Embodiment

FIG. 36 is a diagram for schematically explaining changes in the stateof the detection electrodes coupled to the analog front ends accordingto a fifth embodiment of the present disclosure. FIG. 37 is a diagramfor explaining the coupling circuit according to the fifth embodiment.FIG. 38 is a diagram for schematically explaining a change in the stateof the coupling circuit according to the fifth embodiment in a secondstate, in which the detection electrodes are sequentially switched. FIG.39 is a diagram for schematically explaining a change in the couplingcircuit according to the fifth embodiment in 2×2 collective hoverdetection. FIG. 40 is a diagram for schematically explaining a change inthe state of the coupling circuit according to the fifth embodiment inthe first state, in which the detection electrodes are sequentiallyswitched. Components described in the first to the fourth embodimentsare denoted by like reference numerals, and explanation thereof isomitted.

As illustrated in FIG. 36, the coupling circuit 18 illustrated in FIG.37 switches between the step for touch detection (Step ST31) and thestep for hover detection (Step ST32). Similarly to the fourthembodiment, the coupling circuit 18 switches between the step for hoverdetection (Step ST32) and the step for touch detection (Step ST33 orStep ST34).

The coupling circuit 18 illustrated in FIG. 37 includes switches Mux1,Mux2, Mux3, and Mux4. The relay wire DEL couples the switch Mux1 and theswitch Mux2 to each other, couples the switch Mux1 and the switch Mux3to each other, and couples the switch Mux1 and the switch Mux3 to eachother. Opening and closing of the switches Mux1, Mux2, Mux3, and Mux4allow any one of the supply wiring for the drive signals Vcomdc fordisplay, the supply wiring for the guard signals Vgd, and the analogfront end SC to be coupled to one detection electrode DE in atime-division manner.

At Step ST31 illustrated in FIG. 36, as illustrated in FIG. 38, theswitches Mux2 and Mux3 decouple the relay wires DEL from the analogfront ends SC. The switch Mux1 electrically couples the detectionelectrodes DE(1, n), DE(1, n−4), DE(1, n−8), and DE(1, n−12) to therelay wires DEL(1, n), DEL(1, n−4), DEL(1, n−8), and DEL(1, n−12),respectively. The switch Mux1 couples the other detection electrodes DEto the supply wiring for the guard signals Vgd.

The switch Mux4 electrically couples the analog front end SC1 to therelay wire DEL(1, n). Similarly, the analog front end SC2 iselectrically coupled to the relay wire DEL(1, n−4). The analog front endSC3 is electrically coupled to the relay wire DEL(1, n−8). The analogfront end SC4 is electrically coupled to the relay wire DEL(1, n−12).The analog front end SC5 is electrically coupled to the relay wireDEL(2, n). The analog front end SC6 is electrically coupled to the relaywire DEL(2, n−4). The analog front end SC7 is electrically coupled tothe relay wire DEL(2, n−8). The analog front end SC8 is electricallycoupled to the relay wire DEL(2, n−12). As a result, as illustrated inFIG. 26A, the coupling circuit 18 selects the detection electrodes DE inthe fourth, the eighth, the twelfth, and the sixteenth rows. Thecoupling circuit 18 couples the detection electrodes DE in the fourth,the eighth, the twelfth, and the sixteenth rows to the analog front endsSC denoted by the reference numerals written in the respective detectionelectrodes DE in FIG. 26A.

The switch Mux4 sequentially switches the relay wire DEL to beelectrically coupled to the corresponding analog front end SC, wherebythe coupling circuit 18 selects the detection electrodes DE in thethird, the seventh, the eleventh, and the fifteenth rows as illustratedin FIG. 26B. The coupling circuit 18 couples the detection electrodes DEin the third, the seventh, the eleventh, and the fifteenth rows to theanalog front ends SC denoted by the reference numerals written in therespective detection electrodes DE in FIG. 26B.

Subsequently, the switch Mux4 sequentially switches the relay wire DELto be electrically coupled to the corresponding analog front end SC,whereby the coupling circuit 18 selects the detection electrodes DE inthe second, the sixth, the tenth, and the fourteenth rows as illustratedin FIG. 26C. The coupling circuit 18 couples the detection electrodes DEin the second, the sixth, the tenth, and the fourteenth rows to theanalog front ends SC denoted by the reference numerals written in therespective detection electrodes DE in FIG. 26C.

Subsequently, the switch Mux4 sequentially switches the relay wire DELto be electrically coupled to the corresponding analog front end SC,whereby the coupling circuit 18 selects the detection electrodes DE inthe first, the fifth, the ninth, and the thirteenth rows as illustratedin FIG. 26D. The coupling circuit 18 couples the detection electrodes DEin the first, the fifth, the ninth, and the thirteenth rows to theanalog front ends SC denoted by the reference numerals written in therespective detection electrodes DE in FIG. 26D.

As illustrated in FIGS. 36, 26A, 26B, 26C, and 26D, at Step ST31, thedetection device according to the fifth embodiment can sequentiallyperform touch detection on the whole surface even if the number of thedetection electrodes DE is larger than the number of the analog frontends SC.

At Step ST32 illustrated in FIG. 36, the switches Mux2 and Mux4 decouplethe relay wires DEL from the analog front ends SC. As illustrated inFIG. 39, the switch Mux3 and the relay wires DEL electrically couple thedetection electrodes DE disposed side by side in the first direction Dxand the second direction Dy to one another. The switch Mux3 and therelay wires DEL thus combine 2×2 detection electrodes DE, therebyforming the detection electrode blocks DEB(1, N) to DEB(1, N−7). Thedetection electrode blocks DEB(1, N) to DEB(1, N−7) are coupled to theanalog front ends SC1 to SC7, respectively. The control circuit 11illustrated in FIG. 1 then performs hover detection (Step ST32).

If the detection signals Vdet supplied from the respective detectionelectrode blocks DEB illustrated in FIG. 39 are equal to or higher thanthe predetermined threshold ΔVthb, the detection circuit 40 performs theprocessing at Step ST33.

At Step ST33, the fifth embodiment performs touch detection on thedetection electrode block DEB determined to have a signal intensityequal to or higher than the predetermined threshold ΔVthb and on thedetection electrodes DE around the detection electrode block DEB.

At Step ST33, for example, the detection electrode block DEB(1, N) isdetermined to have a signal intensity equal to or higher than thepredetermined threshold ΔVthb. In this case, as illustrated in FIG. 40,the control circuit 11 performs touch detection on the detectionelectrodes DE(1, n), DE(1, n−1), DE(2, n), and DE(2, n−1) correspondingto the detection electrode block DEB(1, N) (Step ST33).

The switches Mux3 and Mux4 decouple the relay wires DEL from the analogfront ends SC. The switch Mux2 couples the analog front end SC1 to therelay wire DEL(1, n) and couples the analog front end SC5 to the relaywire DEL(2, n). The switch Mux2 then couples the analog front end SC1 tothe relay wire DEL(1, n−1) and couples the analog front end SC5 to therelay wire DEL(2, n−1). The switch Mux2 then couples the analog frontend SC1 to the relay wire DEL(1, n−2) and couples the analog front endSC5 to the relay wire DEL(2, n−2). The switch Mux2 then couples theanalog front end SC1 to the relay wire DEL(1, n−3) and couples theanalog front end SC5 to the relay wire DEL(2, n−3). With thisprocessing, the detection electrodes DE disposed side by side in thefirst direction Dx are simultaneously selected and coupled to the analogfront ends SC. With the operations of the switch Mux2, the detectionelectrodes DE coupled to the analog front ends SC are sequentiallyswitched in the second direction Dy.

After the processing at Step ST33 illustrated in FIG. 32, the controlcircuit 11 performs touch detection on another detection electrode blockDEB determined to have a signal intensity equal to or higher than thepredetermined threshold ΔVthb at Step S32 and on the detectionelectrodes DE around the detection electrode block DEB (Step ST34).Detailed explanation of the processing at Step ST34 is omitted becauseit is the same as the processing at Step ST33 except that the positionsof the detection electrodes DE coupled to the analog front ends SC inthe second direction Dy are different.

Sixth Embodiment

FIG. 41 is a plan view schematically illustrating a relation between thedetection electrodes and the coupling circuit according to a sixthembodiment of the present disclosure. Components described in the firstembodiment are denoted by like reference numerals, and explanationthereof is omitted.

The coupling circuit 18 according to the sixth embodiment includes themultiplexer Mu but does not include the analog front ends SC. The analogfront ends SC are included in the integrated circuit 19, and areprovided separately from the multiplexer Mu. This configuration reducesthe number of circuits, such as TFTs, included in the coupling circuit18 on the first substrate 21, thereby reducing the area of the couplingcircuit 18. As a result, the peripheral region 10 b can be effectivelyused as a space for other elements or downsized to serve as a smallerframe.

While exemplary embodiments have been described, the embodiments are notintended to limit the present disclosure. The contents disclosed in theembodiments are given by way of example only, and various changes may bemade without departing from the spirit of the present disclosure.Appropriate changes made without departing from the spirit of thepresent disclosure naturally fall within the scope of the disclosure.

The shape, the position, and the number of the detection electrodes DEand the pixel electrodes 22, for example, are given by way of exampleonly and may be appropriately modified.

The display device according to the present aspect may have thefollowing aspects, for example.

(1) A detection device comprising:

a substrate;

a plurality of detection electrodes arrayed in a row-columnconfiguration in a first direction and a second direction intersectingthe first direction in a sensor region of the substrate;

a drive circuit configured to supply a plurality of drive signals to thedetection electrodes;

a plurality of wires electrically coupled to the respective detectionelectrodes;

a plurality of analog front ends each configured to receive, from atleast one of the detection electrodes, at least one detection signalcorresponding to a capacitance change in the at least one of thedetection electrodes caused when the drive signals are supplied; and

a multiplexer coupled to one of the detection electrodes via one of thewires and capable of changing the number of the wires simultaneouslyelectrically coupled to one of the analog front ends, wherein

the wires extend in the second direction, and

the wires are disposed side by side in the first direction.

(2) The detection device according to (1), further comprising a controlcircuit configured to control the multiplexer, wherein,

the control circuit changes the number of the detection electrodessimultaneously electrically coupled to one of the analog front endsdepending on a distance between a target object and the detectionelectrodes in a third direction intersecting the first direction and thesecond direction.

(3) The detection device according to (1), wherein the multiplexer isdisposed on the substrate provided with the detection electrodes, and ispositioned outside the sensor region.

(4) The detection device according to (3), wherein the analog front endsare included in an integrated circuit and provided separately from themultiplexer.

(5) The detection device according to any one of (1) to (4), wherein theanalog front ends are disposed on the substrate provided with thedetection electrodes, and is positioned outside the sensor region.

(6) The detection device according to any one of (1) to (5), wherein thenumber of the detection electrodes is larger than the number of theanalog front ends.

(7) The detection device according to any one of (1) to (6), wherein

the detection electrodes electrically coupled to the respective wirescapable of being simultaneously coupled to one of the analog front endsinclude at least two of the detection electrodes disposed side by sidein the first direction or the second direction.

(8) The detection device according to any one of (1) to (7), wherein themultiplexer sequentially electrically couples the wires one by one toone of the analog front ends in a time-division manner.

(9) The detection device according to any one of (1) to (8), furthercomprising a control circuit configured to control the multiplexer ineither one of a first detection mode and a second detection mode, thefirst mode being a mode in which the number of the wires simultaneouslyelectrically coupled to one of the analog front ends is one, and thesecond detection mode being a mode in which the number of the wiressimultaneously electrically coupled to one of the analog front ends ismore than one.(10) The detection device according to (9), wherein the control circuit,in accordance with a control signal, makes the number of the wiressimultaneously electrically coupled to one of the analog front endslarger, as a distance between a target object and the detectionelectrodes becomes larger.(11) The detection device according to (9), further comprising:

a detection circuit configured to process the at least one detectionsignal via the analog front ends, wherein

the control circuit changes the number of the wires simultaneouslyelectrically coupled to one of the analog front ends to decrease thenumber of the wires when the at least one detection signal detected bythe detection circuit is larger than a first threshold.

(12) The detection device according to (11), wherein

the control circuit changes the number of the wires simultaneouslyelectrically coupled to one of the analog front ends to increase thenumber of the wires when the at least one detection signal detected bythe detection circuit is smaller than a second threshold that is smallerthan the first threshold.

(13) The detection device according to (9), wherein

the control circuit, in the second detection mode, determines a firstdetection electrode on which the first detection mode is to beperformed, and performs the first detection mode on the first detectionelectrode and a second detection electrode adjacent to the firstdetection electrode.

(14) The detection device according to any one of (9) to (13), whereinthe detection electrodes disposed side by side in the first directionare coupled to the respective analog front ends in the first detectionmode.

(15) A display device comprising:

the detection device according to any one of (1) to (14); and

a display panel including a display region, wherein

the detection electrodes are provided in a region overlapping thedisplay region.

(16) The display device according to (15), wherein a display period anda detection period are alternately arranged in a time-division manner,and

all the detection electrodes are supplied with a common potential in thedisplay period.

What is claimed is:
 1. A detection device comprising: a substrate; aplurality of detection electrodes arrayed in a row-column configurationin a first direction and a second direction intersecting the firstdirection in a sensor region of the substrate; a drive circuitconfigured to supply a plurality of drive signals to the detectionelectrodes; a plurality of wires electrically coupled to the respectivedetection electrodes, extending in the second direction, and disposedside by side in the first direction; a plurality of analog front endseach configured to receive, from at least one of the detectionelectrodes, at least one detection signal corresponding to a capacitancechange in the at least one of the detection electrodes caused when thedrive signals are supplied; a multiplexer coupled to one of thedetection electrodes via one of the wires and capable of changing thenumber of the wires simultaneously electrically coupled to one of theanalog front ends; and a control circuit configured to control themultiplexer, wherein the control circuit changes the number of thedetection electrodes simultaneously electrically coupled to one of theanalog front ends depending on a distance between a target object andthe detection electrodes in a third direction intersecting the firstdirection and the second direction.
 2. The detection device according toclaim 1, wherein the multiplexer is disposed on the substrate providedwith the detection electrodes, and is positioned outside the sensorregion.
 3. The detection device according to claim 2, wherein the analogfront ends are included in an integrated circuit and provided separatelyfrom the multiplexer.
 4. The detection device according to claim 1,wherein the analog front ends are disposed on the substrate providedwith the detection electrodes, and is positioned outside the sensorregion.
 5. The detection device according to claim 1, wherein the numberof the detection electrodes is larger than the number of the analogfront ends.
 6. The detection device according to claim 1, wherein thedetection electrodes electrically coupled to the respective wirescapable of being simultaneously coupled to one of the analog front endsinclude at least two of the detection electrodes disposed side by sidein the first direction or the second direction.
 7. The detection deviceaccording to claim 1, wherein the multiplexer sequentially electricallycouples the wires one by one to one of the analog front ends in atime-division manner.
 8. A detection device comprising: a substrate; aplurality of detection electrodes arrayed in a row-column configurationin a first direction and a second direction intersecting the firstdirection in a sensor region of the substrate; a drive circuitconfigured to supply a plurality of drive signals to the detectionelectrodes; a plurality of wires electrically coupled to the respectivedetection electrodes, extending in the second direction, and disposedside by side in the first direction; a plurality of analog front endseach configured to receive, from at least one of the detectionelectrodes, at least one detection signal corresponding to a capacitancechange in the at least one of the detection electrodes caused when thedrive signals are supplied; a multiplexer coupled to one of thedetection electrodes via one of the wires and capable of changing thenumber of the wires simultaneously electrically coupled to one of theanalog front ends; and a control circuit configured to control themultiplexer in either one of a first detection mode and a seconddetection mode, the first mode being a mode in which the number of thewires simultaneously electrically coupled to one of the analog frontends is one, and the second detection mode being a mode in which thenumber of the wires simultaneously electrically coupled to one of theanalog front ends is more than one.
 9. The detection device according toclaim 8, wherein the control circuit, in accordance with a controlsignal, makes the number of the wires simultaneously electricallycoupled to one of the analog front ends larger, as a distance between atarget object and the detection electrodes becomes larger.
 10. Thedetection device according to claim 8, further comprising: a detectioncircuit configured to process the at least one detection signal via theanalog front ends, wherein the control circuit changes the number of thewires simultaneously electrically coupled to one of the analog frontends to decrease the number of the wires when the at least one detectionsignal detected by the detection circuit is larger than a firstthreshold.
 11. The detection device according to claim 10, wherein thecontrol circuit changes the number of the wires simultaneouslyelectrically coupled to one of the analog front ends to increase thenumber of the wires when the at least one detection signal detected bythe detection circuit is smaller than a second threshold that is smallerthan the first threshold.
 12. The detection device according to claim 8,wherein the control circuit, in the second detection mode, determines afirst detection electrode on which the first detection mode is to beperformed, and performs the first detection mode on the first detectionelectrode and a second detection electrode adjacent to the firstdetection electrode.
 13. The detection device according to claim 8,wherein the detection electrodes disposed side by side in the firstdirection are coupled to the respective analog front ends in the firstdetection mode.